Is it Safe To Drive With a Cracked Radiator?

By Dan Collins

Published 14:07 pm

If you’ve arrived at this article looking for a quick answer to the question of whether or not it’s safe to drive with a cracked radiator, we’re afraid that answer is ‘no’ (sorry!) Whilst your car will usually still run with a cracked radiator, at least in the initial stages, driving with such a problem is not at all safe, and definitely not advisable. This is because a cracked radiator can directly cause your car to overheat, break down or even catch fire – scary stuff. The reasons for this bleak prognosis become clear when we consider the role of a radiator within the car, and what happens when it cracks or breaks.

What is the Radiator and What does it do?

Firstly, to understand why it isn’t safe to drive with a cracked radiator, it’s important to understand what the radiator is, and how it functions. Unlike the radiators found in your house, the one in your car is not designed to heat anything up – in fact, it does quite the opposite. The radiator is a vital part of your car’s cooling system, which works in conjunction with the engine coolant to remove heat from your engine and transmission. This is necessary to prevent your car from overheating, as the engine creates a lot of heat whilst burning fuel to enable your car to function. The radiator is a large, rectangular metal structure with fins that resembles a grill, located under the hood of your vehicle.

How does the Radiator Work?

The process of cooling down your engine begins with the coolant being pumped through the engine to absorb the heat. The coolant then transports this heat to the radiator, where it is passed through the metal fins and is cooled by air from outside. The radiator fan helps this process, and also blows the hot air out, emitting the heat through the grill at the front of your car. The coolant then returns to the engine and the process is repeated. This is the main way in which heat is removed from the engine, so if any part of this system breaks down, the heat will have no way of escaping and you risk the engine overheating. This is why you should also regularly check your coolant level and top it up if it gets low. The radiator is also often used to cool transmission fluid, again through the use of coolant, which is another of its important functions.

What Would Cause the Radiator to Crack?

There are a variety of factors which might cause your radiator to crack. It can be caused by a faulty thermostat (the part which monitors the temperature of the engine and determines when to release water and coolant) allowing too much coolant into radiator, leading to high pressure inside the radiator, and causing it to break. The same effect could also be caused by a leaking or faulty head gasket – this is one of the worst-case scenarios, as a broken head gasket is a costly fix! Hot weather can affect the radiator function, causing it to have to work much harder to cool the coolant – if there’s not enough fluid in the radiator, this may prove too much of a strain for it, and it may break. Conversely, abnormally cold weather can also cause cracking, if the radiator fluid freezes and expands. Cracks can also occur if the metal of your radiator becomes rusty, which is a particular problem for cars stored by the coast.

How Can You Tell if Your Radiator is Cracked?

If you have a crack in your radiator, it will more than likely be leaking coolant. Coolant is usually a bright color, such as yellow, pink or green. You may notice this on the ground under your car after it has been parked up for a while. If your low coolant light comes on or the level of coolant significantly drops, this is another sign you may have a leak caused by a broken radiator. If it keeps happening, don’t just continue topping up the coolant and hoping for the best – you obviously have a problem and should seek advice from a qualified mechanic. Another clear sign that you may have a problem with the radiator is if your engine seems particularly hot, as this indicates it is overheating. When inspecting your radiator, look for signs of rust, corrosion or discoloration, particularly along the seams, which may indicate a leak caused by a crack.

Is it Safe to Drive With a Cracked Radiator? What Could Happen?

Now that we know the radiator is how heat from the engine gets removed from your car, the reason you shouldn’t keep driving with a cracked radiator should be obvious – your engine is likely to overheat. This can lead to the pistols snapping, causing serious engine damage and resulting in your car breaking down – which is of course extremely dangerous, as it could cause you to lose control and crash the car. If you notice steam coming out from under the hood of your car whilst you are driving, you should pull over immediately and vacate the vehicle, in case it catches fire. If allowed to get to this stage, repairs will be much more extensive and costly than if you had simply repaired or replaced the radiator as soon as you realized it was cracked. For these reasons, it is therefore strongly advised that you do not drive with a cracked or damaged radiator, or one that you suspect might have such a problem.

What Should You do if You Know You Have a Cracked Radiator?

If you know or suspect that your radiator is cracked, or if you notice your car is leaking coolant, you should book it in to be serviced and repaired by a qualified mechanic as soon as possible. In the meantime, cease driving and find an alternative method of transportation. You, and your car, will thank you for it!